WO2004034598A2

WO2004034598A2 - A pmr handset with a removable loudspeaker unit

Info

Publication number: WO2004034598A2
Application number: PCT/EP2003/011119
Authority: WO
Inventors: Mario Micheli
Original assignee: Ote S.P.A.
Priority date: 2002-10-09
Filing date: 2003-10-08
Publication date: 2004-04-22
Also published as: AU2003268925A8; ITTO20020874A1; WO2004034598A3; AU2003268925A1

Abstract

A PMR handset assembly (10) includes a handset unit (20) operable to function autonomously as a cellular telephone and a loudspeaker unit (30) removably connectable to the handset unit (20) to enable the assembly (10) also to function in a 'dispatch' or viva voce mode.

Description

A PMR handset with a removable loudspeaker unit

The present invention relates to a handset for PMR applications with a removable loudspeaker unit. The invention is applicable to all types (analogue and digital) of PMR (Private Mobile Radio) technology and to PMR-derived mobile telephones .

Known PMR handsets incorporate a loudspeaker and are arrangements which represent a compromise between the need to produce a sufficiently high audio volume in viva voce mode and the need to limit the overall size of the handset. PMR handsets are already available which certainly produce a sufficiently high audio volume but are somewhat bulky and uncomfortable to carry round. The other category of handsets available on the market is more compact and easier to handle but has the disadvantage of a somewhat low maximum audio volume, so that this type of handset is of only limited effectiveness, since it is difficult to use in a noisy environment .

The most recent handsets are digital and are used to make telephone calls as well as for PMR applications. PMR handsets offer services which are not available with normal cellular phones, the most important of these being the "dispatch" function. While operating in "dispatch" mode, the handset is not normally held to the user's ear, as a cellular phone would be, but is held at a certain distance from the head or secured to the user's belt. This means that in order for a PMR handset to be able to give out audible communications in a noisy environment it must incorporate a rather powerful loudspeaker. Such loudspeakers are themselves heavy and bulky, meaning that the weight and overall dimensions of the PMR handset are in large part dependent on those of the loudspeaker, required for the possible operation in "dispatch" mode in a noisy environment.

The object of the present invention is therefore to provide a PMR handset assembly operable to overcome the disadvantages and limits described above in relation to the prior art.

This and other objects and advantages, which will be understood better later, are achieved, according to a first aspect of the present invention, by providing a PMR handset assembly having the characteristics defined in Claim 1. Preferential embodiments are described in the dependent Claims . According to another aspect of the present invention a loudspeaker unit is provided as defined in Claim 7.

In this way, a handset of small dimensions can be used for more than one function. For example, the handset can be used in a conventional manner without the loudspeaker unit, like a cellular phone. Alternatively, and according to the present invention, the handset and loudspeaker units can be used together in order to carry out functions usually associated with handsets of larger dimensions. It is sometimes preferable, for example, not to hold the handset next to the user's ear for long periods, owing to the weight of the handset, for instance when the unit is being used to monitor messages when operating in "dispatch" mode.

In the "dispatch" mode, the user can hold the coupled handset and loudspeaker assembly at a distance from his ear, clipped to a belt for example, and still hear messages in "dispatch" mode; or, in a noisy environment, the user can position the loudspeaker unit close to an ear in order to hear and understand better a message being received in "dispatch" mode.

The structural and operating characteristics of a preferred but no -limitative embodiment of a PMR handset assembly according to the present invention will now be described, with reference to the appended drawings, in which:

Figure 1 is a perspective view of a handset assembly according to the present invention in a first operating condition;

Figure 2 is a perspective view of the handset assembly of Figure 1 in a different operating condition, with the loudspeaker unit detached from the apparatus; and

Figure 3 is a perspective view of the handset assembly of Figure 2, seen from a different viewpoint.

With reference to the drawings, a PMR handset assembly according to the present invention is generally indicated 10. The handset assembly 10 includes a handset unit 20 and a loudspeaker unit 30 for releasably coupling to the handset unit 20.

The handset unit 20, as shown in Figures 2 and 3, has an outer body which is preferably convex and substantially parallelepipedal in shape, with an alphanumeric keypad 11 and a display 12 on the surface 13 here defined as the "front" . A recess 17 and an elongate slot 16, formed substantially parallel to the plane of the front surface 13, are formed in each of the opposite side walls 14, 15.

The handset unit 20 incorporates all the functions required to make telephone calls. The manufacturing and operating characteristics of the handset unit 20 are not per se relevant to the understanding of the invention and will therefore not be discussed in any detail.

An important characteristic of the arrangement of the invention consists in the fact that the loudspeaker unit 30, which incorporates a loudspeaker (not illustrated) can be attached to and released from the handset unit in such a way that, when the two units are fitted together, the handset assembly can be used for PMR operation; by removing the loudspeaker unit 30 from the handset unit 20, on the other hand, the user is able to carry and handle a lighter device to make normal telephone calls. When he needs to use the PMR function of the apparatus, the user can easily and rapidly couple the loudspeaker unit 30 to the handset unit 20. Most of the time, the loudspeaker unit 30 can be carried separately from the handset unit 20, in a bag or case for example, while the handset unit can be carried comfortably in a pocket .

In the preferred embodiment shown in the drawings, the loudspeaker unit 30 can be snap-engaged to the handset unit

20. The mechanical snap engagement means also ensure that the two units are connected electrically.

As shown in Figures 2 and 3, the loudspeaker unit 30 defines an open cavity 31 at the bottom, the overall shape thereof matching that of the upper portion of the handset unit 20. The cavity 31 is open at the front 32 in order for the display 12 of the handset unit 20 to be visible when the units are coupled. Longitudinal ribs 33 are formed in opposite sides of the inner surface of the cavity 31, for coupling with the slots 16 formed on opposite sides of the handset unit 20. Two external buttons 34 are provided for disengaging respective clip members 35 which are preferably of a resilient type and can be coupled with the corresponding recesses 17 formed in the sides 14, 15 of the handset unit 20.

The loudspeaker unit 30 includes specific controls for PMR functions, such as a rotatable channel selector knob 36 for locating channels, a volume control 37 for adjusting the volume, an audio power amplifier (not seen in the drawings) for viva voce transmission and a call push-button 38, commonly referred to as push- to-talk or PTT button, which must be pressed in order to make a call in half duplex mode, that is when one of the two callers is speaking and the other listening.

The loudspeaker unit 30 can also incorporate other electrical and or electronic devices (not shown) such as, for example, a bar code reader, for deciphering data transcribed in bar code format on identity documents, dials for fast-dialling, a video-camera for taking and sending photographic images, a fingerprint reader or, in general, any other electronic device operable to transform an image into data for transmitting as a message .

As it will be appreciated, the handset assembly according to the present* invention provides the advantage of separating the loudspeaker unit from the handset unit, thereby providing a handset unit free of the bulk and weight of the loudspeaker unit, when the functions of this latter are not required.

Naturally, the principle of the invention remaining unchanged, embodiments and manufacturing details may vary widely from those described and illustrated, without departing thereby from the scope of the present invention, as identified by the Claims which follow.

Claims

1. A PMR handset assembly, including: a handset unit (20) able to operate autonomously at least as a cellular telephone, and a loudspeaker unit (30) , for releasably coupling to the handset unit (20) in order to enable the assembly (10) also to operate in "dispatch" or viva voce mode.

2. A handset assembly according to Claim 1, in which the loudspeaker unit (30) includes a push-to-talk (PTT) button (38) .

3. A handset assembly according to Claim 1, including fast mechanical coupling means (16, 17; 33, 34, 35) for connecting the loudspeaker unit (30) and the handset unit (20) .

4. A handset assembly according to Claim 1, in which the removable loudspeaker unit (30) also includes at least one from a group consisting of: bar code reader, selector means for fast dialling calls, video-camera means for sending and transmitting photographic images, means for reading fingerprints, means for controlling the volume of the said loudspeaker, an audio power amplifier for the said loudspeaker .

5. A handset assembly according to Claim 1, in which the loudspeaker unit (30) forms a cavity (31) for at least partially engaging the handset unit (20) .

6. A handset assembly according to Claim 5, in which the cavity (31) is shaped (32) so that the display (12) of the handset unit (20) is visible when this is coupled to the loudspeaker unit (30) .

7. A loudspeaker unit (30) operable to be releasably coupled to a handset unit (20) , the loudspeaker unit (30) including means for removably coupling it to the handset unit (20) and means for coupling to a loudspeaker of the handset unit, whereby when the loudspeaker unit (30) and the handset unit (20) are coupled, the loudspeaker unit acts as loudspeaker for the handset unit assembly, with a greater volume than that of the loudspeaker of the handset unit (20) itself .

8. A loudspeaker unit according to Claim 7, including a PTT (push-to-talk) button (38) .

9. A loudspeaker unit according to Claim 7, including rapid mechanical means (33, 34, 35) for coupling it to a handset unit (20) .

10. A loudspeaker unit according to Claim 7, also including at least one device selected from a group consisting of: a bar code reader, selector means for rapid dial calls, video- camera means for taking and transmitting photographic images, means for reading fingerprints, means for controlling the volume of the said loudspeaker, an audio power amplifier for the said loudspeaker.

11. A loudspeaker unit according to Claim 7, in which the loudspeaker unit (30) defines a cavity (31) for at least partially engaging the handset unit (20) .

12. A loudspeaker unit according to Claim 11, in which the cavity (31) is shaped (32) so that a display (12) of the handset unit (20) is visible when this is coupled to the loudspeaker unit (30) .